New magnetic semiconductor material holds promise for 'spintronics'

September 10, 2013, North Carolina State University

Researchers at North Carolina State University have created a new compound that can be integrated into silicon chips and is a dilute magnetic semiconductor – meaning that it could be used to make "spintronic" devices, which rely on magnetic force to operate, rather than electrical currents.

The researchers synthesized the new compound, strontium (Sr3SnO), as an epitaxial thin film on a silicon chip. Epitaxial means the material is a single crystal. Because Sr3SnO is a dilute magnetic semiconductor, it could be used to create transistors that operate at room temperature based on magnetic fields, rather than .

"We're talking about cool transistors for use in spintronics," says Dr. Jay Narayan, John C. Fan Distinguished Professor of Materials Science and Engineering at NC State and senior author of a paper describing the work. "Spintronics" refers to technologies used in solid-state devices that take advantage of the inherent "spin" in electrons and their related magnetic momentum.

"There are other materials that are dilute , but researchers have struggled to integrate those materials on a , which is essential for their use in multifunctional, smart devices," Narayan says. "We were able to synthesize this material as a single crystal on a ."

"This moves us closer to developing spin-based devices, or spintronics," says Dr. Justin Schwartz, co-author of the paper, Kobe Steel Distinguished Professor and Department Head of the Materials Science and Engineering Department at NC State. "And learning that this material has magnetic semiconductor properties was a happy surprise."

The researchers had set out to create a material that would be a topological insulator. In topological insulators the bulk of the material serves as an , but the surface can act as a highly conductive material – and these properties are not easily affected or destroyed by defects in the material. In effect, that means that a topological insulator material can be a conductor and its own insulator at the same time.

Two materials are known to be topological insulators – bismuth telluride and bismuth selenide. But theorists predicted that other materials may also have topological insulator properties. Sr3SnO is one of those theoretical materials, which is why the researchers synthesized it. However, while early tests are promising, the researchers are still testing the Sr3SnO to confirm whether it has all the characteristics of a topological insulator.

Explore further: Scientists make first direct images of topological insulator's edge currents

More information: The paper, "Epitaxial integration of dilute magnetic semiconductor Sr3SnO with Si (001)," was published online Sept. 9 in Applied Physics Letters.

Related Stories

Engineers show feasibility of superfast materials

February 13, 2013

(—University of Utah engineers demonstrated it is feasible to build the first organic materials that conduct electricity on their edges, but act as an insulator inside. These materials, called organic topological ...

Researchers forward quest for quantum computing

May 23, 2013

Research teams from UW-Milwaukee and the University of York investigating the properties of ultra-thin films of new materials are helping bring quantum computing one step closer to reality.

Recommended for you

Scientists create diodes made of light

March 16, 2018

Photonics researchers at the National Physical Laboratory (NPL) have achieved the extra-ordinary by creating a diode consisting of light that can be used, for the first time, in miniaturised photonic circuits, as published ...

Quantum speed limits are not actually quantum

March 15, 2018

Quantum mechanics has fundamental speed limits—upper bounds on the rate at which quantum systems can evolve. However, two groups working independently have published papers showing for the first time that quantum speed ...

Thermally driven spin current in DNA

March 15, 2018

An emerging field that has generated a wide range of interest, spin caloritronics, is an offshoot of spintronics that explores how heat currents transport electron spin. Spin caloritronics researchers are particularly interested ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.